Evolution of the Prevalence of Myopia among Taiwanese Schoolchildren: A Review of Survey Data from 1983 through 2017.

PURPOSE: The aim of this study was to evaluate the changes in the prevalence of myopia in Taiwanese schoolchildren over the past few decades and to analyze the risk factors for myopia. DESIGN: Analysis of 8 consecutive population-based myopia surveys conducted from 1983 through 2017. PARTICIPANTS: An average of 8917 (5019-11 656) schoolchildren 3 to 18 years of age were selected using stratified systematic cluster sampling or by probability proportional to size sampling. METHODS: All participants underwent complete ophthalmic evaluations. Three drops of 0.5% tropicamide were used to obtain the cycloplegic refractive status of each participant. Questionnaires were used to acquire participant data from the 1995, 2005, 2010, and 2016 surveys. MAIN OUTCOME MEASURES: Prevalence of myopia (spherical equivalence of ≤-0.25 diopter [D]) and high myopia (≤-6.0 D) was assessed. Multivariate analyses of risk factors were conducted. RESULTS: The prevalence of myopia among all age groups increased steadily. From 1983 through 2017, the weighted prevalence increased from 5.37% (95% confidence interval [CI], 3.50%-7.23%) to 25.41% (95% CI, 21.27%-29.55%) for 7-year-olds (P = 0.001 for trend) and from 30.66% (95% CI, 26.89%-34.43%) to 76.67% (95% CI, 72.94%-80.40%) for 12-year-olds (P = 0.001 for trend). The prevalence of high myopia also increased from 1.39% (95% CI, 0.43%-2.35%) to 4.26% (95% CI, 3.35%-5.17%) for 12-year-olds (P = 0.008 for trend) and from 4.37% (95% CI, 2.91%-5.82%) to 15.36% (95% CI, 13.78%-16.94%) for 15-year-olds (P = 0.039 for trend). In both the 2005 and 2016 survey samples, children who spent less than 180 minutes daily on near-work activities showed significantly lower risks for myopia developing (<60 minutes: odds ratio [OR], 0.48 and 0.56; 60-180 minutes: OR, 0.69 and 0.67). In the 2016 survey, spending more than 60 minutes daily on electronic devices was associated significantly with both myopia and high myopia (OR, 2.43 and 2.31). CONCLUSIONS: The prevalence of myopia among schoolchildren increased rapidly from 1983 through 2017 in Taiwan. The major risk factors are older age and time spent on near-work activities. Use of electronic devices increased the amount of time spent on near-work and may increase the risk of developing myopia.

Polymorphisms in steroidogenesis genes, sex steroid levels, and high myopia in the Taiwanese population.

PURPOSE: To evaluate the relationship among single nucleotide polymorphisms (SNPs) in steroidogenesis enzyme genes, serum levels of sex steroids, and high myopia in Taiwanese male and female populations. METHODS: A campus-based sample of 283 cases (145 males and 138 females) with high myopia and 280 controls (144 males and 136 females) with low myopia or emmetropia was studied. Estradiol, progesterone, and testosterone levels were determined using enzyme-linked immunosorbent assay kits. We genotyped six SNPs within five steroidogenesis enzyme genes (17 alpha-hydroxylase/17,20 lyase [CYP17A1], 3 beta-hydroxysteroid dehydrogenase [HSD3B1], 17 beta-hydroxysteroid dehydrogenase 1 [HSD17B1], steroid-5-alpha-reductase, alpha polypeptide 2 [SRD5A2], and aromatase [CYP19A1]) using polymerase chain reaction-restriction fragment length polymorphism methods. Student's t-tests, χ(2) tests, logistic regression, multifactor dimensionality reduction (MDR) methods, and ANOVA were used to determine significance. RESULTS: An MDR analysis corroborated the synergistic genotype association and demonstrated that synergistic interaction between rs6203 (HSD3B1), rs10046 (CYP19A1), and sex might confer susceptibility to high myopia (p=0.019). In both male and female subjects, levels of testosterone were significantly higher in cases than in controls; in male subjects, the levels of estradiol were significantly higher and those of progesterone were significantly lower in cases (all p-values <0.001). The rs605059 (HSD17B1), with sex-gene interaction, showed association with estradiol levels in males (p=0.035) and testosterone levels in females (p=0.027). CONCLUSIONS: Testosterone levels correlate with high myopia, and interaction of steroidogenesis enzyme genes and sex may be a modulating factor in sex hormone metabolism and high-myopia risk.

Long-term evaluation of refractive status and optical components in eyes of children born prematurely.

PURPOSE: To evaluate the refractive status and optical components in school age children born prematurely and to examine the risk factors associated with refractive errors. METHODS: The participants were a cohort of children aged 7 to 9 years with gestational age less than 35 weeks or birth weight less than 1500 g. The participants' neonatal histories were reviewed; their refractive status and optical components were measured. The study results were compared with the results of age-matched children from a national survey. RESULTS: Of the 108 children studied, 48 (44%) had retinopathy of prematurity (ROP); 29 (27%) had ROP ≥ stage 3. Compared with the control subjects, the study cases showed higher prevalence of myopia (48% vs. 29%), hyperopia (23% vs. 15%), and astigmatism (73% vs. 41%). Common ocular features included shallow anterior chamber depth (ACD), thick lenses, and steep corneal curvature. The hyperopic cases had the shortest axial length (AL), whereas the myopia cases had significantly shallower ACD and greater LT. Those with a history of ROP had more prominent changes in the anterior segment. Generalized estimating equations showed that refractive errors could be predicted by a combination of optical components. CONCLUSIONS: In children born prematurely, the development of myopia is mainly influenced by anterior segment components, whereas hyperopia is mainly attributable to short AL. Astigmatism is primarily cornea-related. A combination of various optical components results in complicated refractive outcomes. The presence of ROP may be associated with significantly shorter ACD, thicker lens, and higher myopia and astigmatism. (ClinicalTrials.gov number, NCT01045616.).

Association between high myopia and progression of visual field loss in primary open-angle glaucoma.

BACKGROUND/PURPOSE: Taiwan has a very high prevalence rate of myopia. We retrospectively studied the influence of myopia on the progression of visual field (VF) loss in primary open-angle glaucoma (POAG) patients. METHODS: We studied 515 POAG patients for a minimum follow-up period of 5 years. VF examination was performed with Humphrey perimeter, 30-2 SITA standard program, every 6 months. A point-wise numerical comparison was applied to judge the VF changes. Test points showing more than 1.0 dB of sensitivity loss in mean defect were identified. A location was considered to have progression if it was detected on two consecutive visits. Progression of VF loss was confirmed if three or more test points deteriorated. Multivariate logistic regression was used to evaluate the association between progression of VF loss and various risk factors. RESULTS: There were 262 cases. Progression of VF loss occurred in 57 eyes (21.8%) during the 5-year follow-up period. Logistic regression revealed that the deterioration was associated with older age, higher mean intraocular pressure, larger vertical cup-to-disc ratio, and greater myopic refraction status. The incidence of VF loss progression was 15.1% in the group of eyes with myopia less than -3 D, 10.5% in the group with -3 D to -6 D, 34.4% in the group with -6 D to -9 D, and 38.9% in the group with myopia greater than -9 D. CONCLUSION: POAG patients with myopia greater than -6 D had a greater progression of VF loss.

The association of single nucleotide polymorphisms in the MMP-9 genes with susceptibility to acute primary angle closure glaucoma in Taiwanese patients.

PURPOSE: To study the relationships between single nucleotide polymorphisms (SNPs) of extracellular matrix, matrix metalloproteases (MMPs), tissue inhibitors of MMPs, and other glaucoma-associated genes and acute primary angle closure glaucoma (PACG). METHODS: We extracted DNA samples from 78 adult patients with acute PACG and 86 control subjects to study the relationships between these specific genes and acute PACG. Genotyping was performed for 35 genes by the GenomeLab SNPstream genotyping system after PCR amplification of chromosomal DNA. The association between these genetic polymorphisms and risk of primary PACG was estimated by chi2 and logistic regression. RESULTS: The genotyping success rate was 99%. Genotyping for the MMP9 site (rs2664538) was significantly different between the two groups (p=0.000001) and the odds ratio was 2.586 (95% CI: 1.715-3.898, p<0.00001). However, there were no associations of SNPs to other genes in patients with acute PACG. CONCLUSIONS: Our results reveal that SNP rs2664538, which is located at the MMP9 gene, is likely to be associated with acute PACG.

Transforniceal lateral deep bone decompression--a modified technique to prevent postoperative diplopia in patients with disfiguring exophthalmos due to dysthyroid orbitopathy.

BACKGROUND/PURPOSE: Postoperative diplopia remains a significant complication of orbital decompression in dysthyroid orbitopathy. This study evaluated the results of orbital decompression treatment using a transforniceal approach to sculpt the lateral orbital deep bone area. METHODS: The two areas of bone in the deep lateral orbit (the basin of the inferior orbital fissure and the sphenoid door jamb) were exposed using a transforniceal swinging eyelid approach. An electric drill was used to sculpt these deep bone areas of the lateral orbit, and approximately 1 mL intraconal fat was removed simultaneously. Between October 1999 and March 2003, transforniceal lateral deep bone decompression was performed in 35 consecutive patients (62 orbits) with disfiguring dysthyroid orbitopathy. Data on proptosis reduction effect, new-onset diplopia and other complications of lateral wall decompression were analyzed. RESULTS: The average preoperative Hertel value was 21.2 +/- 1.3 mm (range, 18-23 mm) and decreased to 17.4 +/- 1.2 mm (range, 15-19.5 mm) postoperatively. The mean decrease in proptosis 3 months postoperatively was 3.8 +/- 0.91 mm (range, 1.5-4.6 mm). New-onset downgaze diplopia occurred in two (5.7%) of the 35 patients. Persistent trigeminal paresthesia was noted in one patient (2.8%). No cerebrospinal fluid leak, globe injury or vision deterioration was noted during 9.5 +/- 1.7 months of follow-up. The cosmetic appearance was improved in all patients after surgery. CONCLUSION: Transforniceal lateral deep bone decompression produces less new-onset, persistent diplopia than traditional inferomedial wall decompression, and provides good cosmesis by using a hidden small incisional wound. This approach appears to be a safe and effective procedure for patients with disfiguring exophthalmos, especially for Asian patients without crease fold.

A predictive model for postoperative intraocular pressure among patients undergoing laser in situ keratomileusis (LASIK).

PURPOSE: The aim of this study was to develop a predictive model based on preoperative variables for estimating postoperative intraocular pressure (IOP) of those eyes undergoing LASIK surgery, to predict the amount of underestimated IOP after LASIK for myopia and myopic astigmatism. DESIGN: Pretest-post-test longitudinal study. METHODS: Both eyes of 193 eligible subjects who underwent LASIK procedures at the Department of Ophthalmology, National Taiwan University Hospital, from July 2000 to December 2002 for myopia and myopic astigmatism were identified to build up the predictive models. IOPs were measured with noncontact air-puff tonometry. Information on age, gender, preoperative central corneal thickness (CCT), preoperative central corneal curvature (CCK), preoperative spherical equivalent refractive error, and ablation depth was collected and applied for predicting postoperative IOP after LASIK based on linear mixed model. RESULTS: Significant predictors for postoperative IOP after myopic LASIK procedures included age, gender, preoperative IOP, ablation depth, preoperative CCT, and preoperative spherical equivalent refractive errors. The linear mixed model, taking into account these significant preoperative correlates and the correlation of IOPs between both eyes of the same patient, explained 91% of the variation of postoperative IOP. CONCLUSIONS: A statistical model was developed for predicting the amount of underestimated IOP after LASIK for myopia and myopic astigmatism, which is of clinical importance to uncover ocular hypertension among patients whose information on postoperative IOP immediately after LASIK is not available.

Metastatic choroidal tumors in Taiwan: an 11-year experience.

PURPOSE: To report the clinical features, the primary sites, and overall prognosis of choroidal metastasis. DESIGN: Observational case series. METHODS: Included were all cases of choroidal metastases evaluated at National Taiwan University Hospital over an 11-year period. Patients with blood or lymphoproliferative diseases were excluded. Clinical features were correlated with disease entity and prognosis. RESULTS: A total of 36 patients with choroidal metastases were identified. The mean age was 53.9 +/- 12.8 years. The mean follow-up period was 5.1 +/- 4.2 months. The primary sites of tumors were lung in 18 (50%), breast in eight (22.2%), gastrointestinal tract in three (8.3%), pancreas in two (5.6%), ovary in two (5.6%), kidney in one (2.8%), liver in one (2.8%), and unknown in one (2.8%). Twenty-two patients (61%) died during follow-up. Mean life span after diagnosis was 4.3 months in these 22 patients. CONCLUSIONS: Lung and breast cancers represent more than two thirds of primary tumor sites. Choroidal metastases may indicate terminal status of the underlying malignancy and short survival time.

Prevalence of anisometropia in Taiwanese schoolchildren.

BACKGROUND AND PURPOSE: This study investigated the prevalence and distribution of anisometropia in Taiwanese schoolchildren using nationwide data from refractive surveys performed in 1995 and 2000. METHODS: Complete survey data was obtained for 11,175 students in 1995 and 10,878 students in 2000. The refractive status of each student was measured using an autorefractometer under cycloplegia and rechecked with retinoscopy. The difference in refractive status between each participant's eyes was determined. Chi-squared statistic was used to assess the difference between the 2 surveys. Multiple linear regression was used to determine the trend and effects of covariates. RESULTS: Most of the schoolchildren (77.6% in 1995, 71.9% in 2000) were not anisometropic. Most of the anisometropic differences were in the range 0.5 to 1.0 D (14.1% in 1995 vs 17.9% in 2000). About 6% of schoolchildren in 1995 and 7.0% in 2000 had anisometropic differences in the range from -1.0 to -2.0 D. Fewer than 4% of students had a level of anisometropia greater than 2.0 D (2.7% vs 3.2%, respectively). The prevalence of anisometropia and the extent of anisometropic difference both increased with age and with maximal myopic refraction (both p < 0.0001). Both the prevalence and extent of anisometropia showed significant differences between the 2 surveys (both p < 0.0001). CONCLUSIONS: Most of the Taiwanese schoolchildren surveyed were non-anisometropic. The prevalence and amount of anisometropia were significantly increased from 1995 to 2000. The mechanisms responsible for these increases have not been determined, but may be related to increase of myopic refraction.